Engine priming means



w. A. PARKINS ET AL ENGINE PRIMING MEANS I Filed June 25, 1935 2 Sheets-Sheet 1 HI gz I N V EN TORS WR/GHT I 7. P/w/rws A TTORNEYS.

Patented May 24, 1938 PATENT OFFICE ENGINE PRIDHNG MEANS Wright A. Parkins, West Hartford, and Alfred B. Marshall, West. Bloomfield, Conn., assignors, by mesne assignments, to United Aircraft Corporation; a corporation of Delaware Application June 23, 1933. Serial No. 877.214 Claims. ,(01. 123-.18'i.5)

This invention relates-to an improvement in priming means adapted primarily for use with internal combustion engines, and is shown as applied on a type of engine-adapted to be used in aircraft. I

It is, sometimes desirable to inject fuel into the cylinders or into-a passage leading to the cylinders of an internal combustion engine to assist in quickly starting the engine. It is always desirm able, however, to reduce the number of parts required to operate an engine and also tokeep the fuel which is often highly inflammable out of the compartments occupied by passengers in a vehicle 'andlespecially is this true in the aircraft 1 industry. I

With these features in mind, an-object of this invention is to provide means for priming an engine.

Another object oithis invention is to provide such priming means without bringing .the priming fluid into the passenger compartments.

Still another object of this invention is to provide an engine priming means which shall be simple, compact and when added on to engine will require but a small amount of additional mecha- Further and other objects and advantages will be apparent from the specification and claims and from the accompanying drawings which illusao trate what is now considered the preferred embodiment.

i Fig. 1 is aside elevation of an engine showing the priming means attached thereto.

Fig. 2 is a diagrammatic sketch showing the 35 Priming means and its connections.

Fig. 3 is a side view 01' an airplane with the priming device installed.

Fig. 4 is a detailed view of the pump and valve operating mechanism.

40 Fig. 1 shows the outline of an engine adapted for aircraft use and having a crankcase and cylinder 22. The propeller hub has been indicated by the numeral 24 and the blower section by the numeral 28. Fuel is supplied to the en ine 45 from carburetor 28, passing through conduit rear section 32, blower section 26 and intake pipe II, and thence into cylinder 22. The carburetor is supplied with a throttle valve and its operating lever, indicated by numeral 38, and with an acso celerating pump 38. The accelerating pump is connected with the throttle mechanism by a. con" nection lli that operation of the throttle lever 36 will operate the accelerating pump. The carburetor is also supplied with a lever 42 which is adapted to change the ratio of fuel to air in the mixture produced by the carburetor which lever is commonly known as a mixture control lever. The mechanism thus far described is a standard commercial engine and carburetor.

A valve 44, havingan operating lever 45 secured thereto, is provided preferably inthe carburetor housing and is operatively connected to the mixture control lever 42 by a link 46 so that operation of the mixturecontrol lever will cause operation of the valve 44. The accelerating pump 3| is 10 adapted to inject fuel into the mixture passage or conduit ill of the carburetor during opening movements of the throttle valve so that when the engine is running and the throttle valve is suddenly opened, a richer mixture will be tempo- 1 rarily supplied to the engine. In the device illustrated, movements of the throttle lever 30 to open the throttle will cause a downward movement of the connection 40 and the accelerating pump plunger 48. This will cause fuel entrapped in the space 50 to be forced through the conduit l2, valve 44, conduit 54 and out through the accelerating jet 56 into the conduit 30.

The valve 44 is adapted to be turned into a position such that communication is established between conduit 52 and conduit 58. when the valve is turned to this last named position, actuation of the accelerating pump plunger will cause fuel entrapped in the space 50 to be forced through conduit 52, valve ll, conduit 5' and into 30 the cylinder 22. II it is not convenient or desirable to injectthe fuel directly into the cylinder 22, it may be injected into an intake conduit adjacent the cylinder, such as conduit 34, or it may be injected into the blower section 26. It will thus be seen that by proper manipulation of the valve 44, the engine may be primed by actuation of theaccelerating pump.

The valve 44 may be operatedby any convenient mechanism and in the embodiment illustrated it is operated by movement of the mixture control lever 42. when the mixture control lever is placed in what is commonly known as full lean position, shown in dotted lines in Fig. l, the valve lever is turned to the position shown in dotted 45 lines in Fig. 1 thus turning the valve 44 to connect conduit 52, with the conduit 58. In all other positions of the mixture control lever, the valve 44 connects the conduit 52 with the conduit 54 so that the carburetor operates in its usual manner. It'will thusbe seen that we have provided a priming device that is simple in construction and overcomes many of the disadvantages of the present priming devices.

In the usual construction, the engine is placed 55 in a compartment or portion of a vehicle common'ly called the engine compartment and indicated by reference numeral 66 in Fig. 3. In aircraft, and particularly in airplanes, the engine compartment is separated from the pilots and/or the passenger compartment, indicated by reference' numeral 6! in Fig. 3, by a partition known as a fire wall, and the engine controls are extended through this fire wall to a position within convenient reach of the pilot or operator. In the accompanying drawings, we have shown this partition separating the engine and pilot's compartment as a wall ill and have indicated the throttle valve control means, which also operates the fuel pump, as a rod 02, and the mixture control means, which also operates the valve 44, as a rod I.

The operation of this device is as follows in starting an engine. The mixture control lever is set at full lean", thereby operating the valve 14 so as to connect the accelerating pump with the priming connection. The throttle rod 62 is then oscillated several times as in opening and closing the throttle, thereby actuating the accelerating pump plunger II to inject fuel into the priming connections. The mixture control is then set to the desired starting position, and the engine crank shaft rotated in the usual manner. It will thus be seen that we have provided a device which is also simple in operation as well as simple in construction. As it is usual, especially in aircraft practice, to bring an operating connection from the mixture control lever to the driver's compartment and also bring a connection from the throttle lever to the driver's compartment, it is apparent that we have provided an efficient priming device without bringing any additional controls, or any fuel connections into the drivers or passenger's compartment.

It is to be understood that the invention herein described is not limited to the specific embodiment illustrated and described but may be used in various other forms without departure from its spirit, as defined by the following claims.

What we claim as new and desire to secure by Letters Patent is:

1. In combination with an engine, a carburetor having a fuel pump, a Jet, and mixture control operating means, an engine priming connection, a valve for selectively directing fuel from said pump to said jet or to said engine priming connection and means connecting said mixture control operating means and said valve whereby operation of the mixture control operating means will operate the valve.

2. In combination, means comprising a carburetor having a throttle valve, an accelerating pump operatlvely connected therewith, an accelerating ,iet, an engine priming connection, and a valve adapted to direct fuel from said pump to either said accelerating jet or said priming connection, mixture control operating means associated with said carburetor, and means operatively connecting said mixture control operating means and said fuel directing valve, a single means for operating said throttle valve and said accelerating pump, and a single means for operating said mixture control operating means and said fuel directing valve.

3. In combination with an engine, a carburetor, a fuel conduit between said carburetor and said engine, a throttle valve in said carburetor, manually controllable means for actuating said throttle valve, a mixture control valve, manually contrpllable means for actuating said mixture control valve, and a pump actuated by said throttle valve actuating means to supply a metered quantity of additional fuel to said engine on opening movement of said throttle valve, a three-way valve connected with the outlet of said pump, a conduit connecting said three-way valve with said carburetor, a second conduit connecting said three-way valve with said fuel conduit, and a connection between said tli'ree-way valve and said mixture control valve actuator for actuating said three-way valve to selectively direct the fuel discharged from said pump into said first mentioned conduit or into said second mentioned conduit.

4. In a carburetor for a multi-cylinder internalcombustion engine provided with an intake manifold, a throttle actuated acceleration pump, a 2' mixture control valve, a branched outlet from said acceleration pump having one branch leading to the mixing chamber of the carburetor and the other branch leading to the engine cylinder adjacent the connections with the intake manifold. a valve for selectively connecting the acceleration pump with either of said branches, and common manual means for simultaneously actuating said valves.

5. In an internal combustion engine, a manifold, a carburetor including a maininduction passage, a throttle valve controlling the induction passage, a fuel reservoir, an acceleration pump for supplying fuel to the induction passage anterior to the throttle valve when the throttle is moved in the opening direction, connecting means between the acceleration pump and the manifold, and valve means for directing the fuel supplied by the acceleration pump to the manifold under certain operating conditions.

WRIGHT A. PARKINS. ALFRED H. MARSHALL. 

